Excerpt: In 1977, in the very heavenly dawn of London’s punk-rock scene, a crude, photocopied magazine told its readers: “This is a chord, this is another, this is a third. Now start a band.” They did so by the thousand. Now that punk aesthetic has come to science. Citizen science has been around for ages—professional astronomers, geologists and archaeologists have long had their work supplemented by enthusiastic amateurs—and new cheap instruments can usefully spread the movement’s reach.